Before you shut down your old email address completely, you might want to set up an auto-reply feature so your contacts will know where to find you. In most cases, you can use your email program to send an automatic reply with your new email address to anyone who emails your old address. For example, on a Mac go to Mail > Preferences > Rules > Add Rule. Or on a PC you can use the auto-reply feature (the same as you would if going on vacation). You can also usually set up auto-replies via your Internet service provider’s web site.